Sound reproducing apparatus



0 H. H. STEGLICH ,5

SOUND REPRODUCING APPARATUS Filed Jan. 6, 1969 i I i i 55 AA lll FIG.1

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u w u m w u m. h A u H m W 7. 9 I Y 6 l l 0 h .w m w mm W, U TS AH nH 8 fi 4 m6 b a e H m Receiver Amplifier Circuits United States Patent Ofice 3,533,669 Patented Oct. 13, 1970 3,533,669 SOUND REPRODUCING APPARATUS Herbert H. Steglich, Wilmette, Ill., assignor to Zenith Radio Corporation, Chicago, 111., a corporation of Delaware Filed Jan. 6, 1969, Ser. No. 789,260 Int. Cl. A47b 81/06, 96/00 US. Cl. 312-8 4 Claims ABSTRACT OF THE DISCLOSURE A cabinet for a stereophonic sound reproducing apparatus such as a radio receiver, wherein rotatable louvers are provided over each of the speaker ports to conceal the ports when the receiver is de-energized. When the receiver is energized an electric motor automatically rotates the louvers to an open position so as not to interfere with sound reproduction by the speakers. The louvers are automatically returned to a closed position upon deenergization of the receiver.

BACKGROUND OF THE INVENTION The present invention relates to stereophonic sound reproduction apparatus, and more particularly to such apparatus having a louvered cabinet for concealing the speaker ports thereof.

SUMMARY OF THE; INVENTION It is a general object of the present invention to provide a new and improved sound reproduction apparatus of the louvered cabinet type.

It is a more specific object of the invention to provide such an improved apparatus which afiords improved convenience and ease of operation while achieving optimum aesthetic and operational usage of a louvered cabinet construction.

In accordance with the invention, sound reproducing apparatus having energized and de-energized operating states includes a cabinet with at least one speaker and associated speaker port. Further included are means comprising a plurality of louvers disposed in front of the speaker port and rotatable into a closed position for concealing the port and into an open position for permitting substantially free passage of sound through the port. Means responsive to the operational status of the apparatus are included for positioning the louvers in an open position when the apparatus is in an energized state and in a closed position when the apparatus is in a deenergized state.

BRIEF DESCRIPTION OF THE DRAWING The aspects of the invention which are believed to be novel are set forth with particularity in the appended claims. The organization and manner of operation of the invention, together with the further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing, in the several figures of which like reference numerals identify like elements, and in which:

FIG. 1 is a perspective View showing a stereophonic radio receiver cabinet incorporating an automatic louver arrangement in accordance with the invention.

FIG. 2 is a cross-sectional view taken along lines 2-2 of FIG. 1.

FIG. 3 is a schematic diagram, partially in block form,

of an electrical control circuit and electro-mechanical ac- DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the invention is practiced in the form of a combination stereophonic radio receiver and record player cabinet 10 of the console type having respective speakers for reproducing left and right stereophonic channels. Four louvers, collectively identified as 11, cover the left speaker port 12, which is preferably covered with an acoustically-transparent grill cloth, and four additional louvers, collectively identified as 13, cover the right speaker port 14. When the receiver is not being operated the louvers assume a coplanar position and completely cover their respective speaker ports, appearing outwardly much like the center section 15 of cabinet 10.

Referring to FIG. 2, it is seen that each of the portlouver combinations 11, 12 and 13, 14 has associated with it a loudspeaker, 16 and 17, respectively. Furthermore, each of the louvers is mounted to the cabinet in a manner which allows it to pivot, and the louvers associated with the left channel, i.e. speaker 16, are coupled together so as to pivot in unison by a tie rod 18. Associated with the innermost louver of this assembly is a lever 19, which is connected by a tie rod 20 to one end of a bellcrank 21. Similarly, the louvers associated with the right channel are coupled by a tie rod 22, and the innermost louver of the assembly has associated with it a lever 23 which is coupled by a tie rod 24 to a bellcrank 21.

Bellcrank 21 is rotatably mounted on a shaft 25 which is coupled by appropriate gearing to an actuator motor 26. The bellcrank is constrained to rotate within a predetermined are by spring-cushioned stop assemblies, 27 and 28, the extent of this are being such that as bellcrank 21 traverses its complete rotational range in a counter-clockwise direction the louvers are rotated from a fully open position to a fully closed position.

Motor 26 is of the electrically reversible type, and in FIG. 3 is seen to have associated with it a pair of single-pole single-throw rotational limit switches 29 and 30, which may be included in stop assemblies 27 and 28, respectively, to limit the rotation of bellcrank 21 by the motor to an amount just sufiicient to open and close the louvers. The radio receiver and phonograph amplifying circuits of the listening instrument are collectively identified by block 31, and are supplied with AC operating power via a double-pole double-throw ON-OFF power switch 32. One section of this switch is serially connected between receiver circuit 31 and the AC line to supply operating power to circuits 31 in the ON position and the other section to connect one side of the AC line to the counterclockwise winding of motor 26 in the ON position, and to the clockwise winding in the OFF position. Limit switches 29 and 30 are serially included between switch 31 and the respective counterclockwise and clockwise windings of motor 26 to interrupt current flow to the motor when the motor has reached the full extent of its travel. The common terminal of motor 26 is connected to the unswitched side of the AC line, which is also connected directly to receiver circuits 31.

When the receiver and amplifier circuits are energized by placing switch 32 in the ON position, the counterclockwise winding of motor 26 is energized, causing bellcrank 21 to be rotated to its most counterclockwise position to open the louvers, at which time switch contacts 29 open to prevent further rotation of the motor. Conversely, when circuit 31 is de-energized, by placing switch 32 in the OFF position, the clockwise winding of motor 26 is energized, causing bellcrank 21 to be rotated to its most clockwise posititon to close the louvers, at which time switch contacts 30 open to prevent further rotation of the motor. Thus, the louvers are automatically opened during operation of the receiver and automatically closed when the receiver is not being operated.

The invention provides an economical but highly desirable sales feature in permitting a stereo home listening instrument cabinet to have maximum aesthetic appeal as an item of furniture when the instrument is not in use. Of course, alternate means are possible for opening the louvers when the receiver is energized, such as worm-gear drives and cable-solenoid arrangements. Furthermore, the louvers could be opened in response to the cabinet lid being opened, perhaps by a form of mechanical linkage.

While a particular embodiment of the present invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broad aspects. Accordingly, the aim in the appended claims is to cover all such changes and modifications as may fall within the true spirit and scope of the invention.

I claim:

1. Sound reproducing apparatus having energized and de-energized operating states, comprising:

a cabinet with at least one speaker and associated speaker port;

means comprising a plurality of louvers disposed in front of said speaker port and rotatable into a closed position for concealing said port and into an open position for permitting substantially free passage of sound through said port; and

means responsive to the operational status of said apparatus for positioning said louvers in an open position when said apparatus is in an energized state 4 and in a closed position when said apparatus is in a de-energized state. 2. Sound reproducing apparatus as described in claim 1 wherein said positioning means comprises an electromechanical actuator mechanically coupled to said louvers. 3. Sound reproducing apparatus as described in claim 2 wherein said apparatus has associated with it a power switch having on and off positions for controlling its operational status, and said positioning means is electrically coupled thereto and responsive to the position thereof.

4. Sound reproducing apparatus as described in claim 3 wherein said apparatus is operational from an external power source, said electro-mechanical actuator includes a reversible motor having clockwise and counterclockwise windings operable from said source, and said power switch has a first section serially connected between said power source and said apparatus for energizing said apparatus when said switch is in said on position and a second section connected between said source and said motor windings for energizing one of said windings when said switch is in said on position and the other of said windings when said switch is in said off position.

References Cited UNITED STATES PATENTS 3,301,952 1/1967 Reznik 3128 FOREIGN PATENTS 326,595 3/1930 Great Britain.

PATRICK D. LAWSON, Primary Examiner US. Cl. X.R. 312-223, 324, 329 

